Depression is the second leading cause of disability and has the highest burden of disease in the US. The PI's career goal is to become an independent investigator designing, evaluating, and implementing novel technology-based interventions for the treatment and prevention of depression. Behavioral intervention technologies (BITs), showing great promise in treating depression, require experts who can integrate an understanding of empirically-based techniques for behavior change with the effective design and application of technologies. This proposal outlines a plan to achieve this goal, through the culmination of training and research plans into a successful R01 proposal. The training plan takes full advantage of the candidate's strong institutional support and environment at Northwestern University's Feinberg School of Medicine and the NIMH- funded Center for Behavioral Intervention Technologies, which is led by the primary mentor for this proposal. Training goals necessary to the PI's career goal create expertise in: 1) creation and evaluation of BITs, especially for use in existing healthcare systems; 2) user-centered design and usability testing; 3) dissemination and implementation; and 4) advanced professional development. This plan builds on the PI's background in clinical psychology, including his past research on Internet-based, self-help interventions for mental and behavioral health including depression treatment and prevention, well-being promotion, and smoking cessation, and a clinical focus on cognitive-behavioral treatments. In this K08, the PI will expand his work to include new modes (e.g., mobile application) and settings (community clinics) of dissemination of BITs. The long-term goal of the research is to integrate BITs into existing healthcare settings thus increasing the efficacy of existing psychological treatments for depression. To this end, the research plan will develop a technology-based treatment support system (TSS) with both patient and therapist-facing features to be used as an adjunct for cognitive-behavioral therapy for depression thus increasing its efficacy. This will be achieved through the following specific aims: 1) conduct user-centered design and usability testing to refine features and tools of the TSS and determine feasibility and acceptability of their use patients and therapists; 2) conduct a randomized pilot trial of the TSS as an adjunct to depression treatment compared to regular treatment alone; and 3) obtain preliminary data assessing efficacy the TSS, changes in mechanisms to be related to efficacy, and system-level factors that would facilitate or retard its adoption, implementation, and sustainability. These studies are expected to advance the design of BITs, improve and increase their use in clinical settings, and ultimately increase the impact of evidence-based practices. Furthermore, these studies will provide the preliminary data for an R01 to conduct a larger RCT. The PI will obtain critical interdisciplinary skills through mentorship from experts in psychology and engineering. Through these experiences, the PI will gain the expertise necessary for a successful career as an independent investigator.